Fix dead code elimination optimization removes assignment on shadowing module constants

Author: aNNiMON

ownlang-parser/src/main/java/com/annimon/ownlang/parser/optimization/DeadCodeElimination.java

@@ -30,7 +30,7 @@ public class DeadCodeElimination extends OptimizationVisitor<Map<String, Variabl
 
     @Override
     public Node optimize(Node node) {
-        final Map<String, VariableInfo> variableInfos = VariablesGrabber.getInfo(node);
+        final Map<String, VariableInfo> variableInfos = VariablesGrabber.getInfo(node, true);
         return node.accept(this, variableInfos);
     }
 
@@ -99,7 +99,7 @@ public Node visit(WhileStatement s, Map<String, VariableInfo> t) {
 
     @Override
     public Node visit(AssignmentExpression s, Map<String, VariableInfo> t) {
-        if (!isVariable((Node)s.target)) return super.visit(s, t);
+        if (!isVariable(s.target)) return super.visit(s, t);
 
         final String variableName = ((VariableExpression) s.target).name;
         if (!t.containsKey(variableName)) return super.visit(s, t);